Accounts Receivable (Allowance for Doubtful Accounts Rollforward) (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance at beginning of period	$ 36	$ 462
Provision adjustment - expense, net of recoveries	0	4
Write-offs and other adjustments - additions (deductions) to receivable balances	(3)	(141)
Balance at end of period	$ 33	$ 325